1. Field of the Invention
The present invention relates to packaging of compressible insulating products, in particular for the purpose of transporting or storing them. More specifically, the invention relates to a method for producing a load of fibrous insulating products in a unitary condition in the form of a roll or of a substantially parallelepiped set of panels, the products in the unitary condition preferably being covered with a protective envelope, made for example of kraft paper or a film of plastic material.
2. Description of the Related Art
Fibrous insulating products are very voluminous products which have a relatively low mass, with densities of approximately 15 kg/m.sup.3, for example, being common. The relative cost of transporting and storing these products is thus high. Additionally, mineral wool can absorb considerable quantities of water, and the products must therefore not be exposed to rain or other bad weather conditions. It is known for these products to be maintained in a unitary condition in an envelope, which is also used to maintain the product in the rolled condition, or to assemble a series of several panels into a set. However the envelope generally does not cover all of the outer surface of the product, and is therefore insufficient for providing full protection against bad weather conditions. Furthermore, in order to simplify loading and unloading operations, these products are preferably palletized, i.e. packaged in loads of approximately ten, or a few tens of units, the load being positioned on a pallet, in order to facilitate handling thereof. The load is provided with a sheath or any other equivalent means compatible with. transport on vehicles not covered with a tarpaulin, and without outdoor storage.
A load of this type is known from French patent FR-79.17771, and uses shaped boards and ties at right angles to one another supported on these boards, the former acting as straps, and the latter comprising supports. The assembly is finally protected by a sheath. Additionally, it is known from European patent EP-B-72 302 to stack insulating packages, the stack delimited by rigid flat components, and subjected to a series of compressions. The stacks are then assembled according to groups by means of cases or of enveloping structures using boards, beams and other hooping means, which form a type of case. As in the previous case, the assembly is protected by a sheath. In both these patents, the load is obtained by using a series of structural components such as boards, stiffeners, cases, etc., each of which constitutes waste to be destroyed during the unpackaging process, and which obviously increases the cost of packaging the products.
This disadvantage is eliminated in the method known according to European patent EP-B-220 980, consisting of the formation of a series of modules, formed by stacking a given number of products, compression in the direction of stacking, and assembly of these products via a film which forms a sealed band due to self adhesion or welding, then superimposition of these modules, two modules being in contact along their parallel surfaces in the direction of the compression exerted during production of the modules. The stacks of modules thus constituted are preferably assembled by means of a film wrapped about the stack. The subdivision of the load into a series of modules is especially advantageous during the unpackaging operations, but requires an installation station reserved specifically for the formation of these modules. Moreover, the cost of the bands increases that. of the packaging.
It must be emphasized that although all the solutions known according to the prior art appear to be relatively complex, this is because it is always necessary to take the greatest possible care, bearing in mind the relatively fragile nature of fibrous insulating products, and in particular to prevent the packaging from causing permanent deformations which would, for example, adversely affect the capacity for recovering the initial volume during unpackaging, since the unit products, and in particular the rolls, are already highly compressed.